1. Field of the Invention
The invention relates to the field of luminous illumination and/or signaling, especially for an automotive vehicle. More precisely, the invention relates to the field of luminous illumination and signaling by means of light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs).
2. Description of the Related Art
An OLED diode consists of a superposition of a plurality of organic semiconductor layers between two electrodes one of which is transparent. The transparent electrode is customarily made of indium tin oxide (ITO). The main feature of indium tin oxide is its combination of electrical conductivity and optical transparency. However, a compromise must be reached during the film deposition, the increase in the concentration of charge carriers inducing an increase in the conductivity of the material, but also a decrease in its transparency. In other words, an electrode made of ITO with a good level of transparency has a limited conductivity.
Published patent document WO 2009/101579 A1 discloses a luminous module comprising an areal OLED light source and an optical device. The OLED light source is segmented so as to make it possible to modulate the light beam produced. For this purpose, it comprises an anode divided into two portions that are electrically independent from each other, and a common cathode, an organic light-emitting layer being placed between the anode and the cathode. Electrical connections are made to the two portions of the anode and to the cathode at different locations in the module and more precisely on opposite edges thereof. Specifically, the module is intended to serve as an illuminating module to be mounted on or in a wall. In this case, the back face of the module is in principle accessible in order to allow an electrical power supply to be connected thereto. Such a solution is however not favorable to projectional mounting of a holder of the module or to decreasing the thickness of the module.
Patent document DE 20 2014 101 538 U discloses a luminous module, especially for an automotive vehicle, comprising an areal OLED light source. This light source is divided into a plurality of zones that are activatable independently of one another. To do this, the areal diode consists of a stack of electrodes, with an organic light-emitting layer between each pair of adjacent electrodes. Each pair of adjacent electrodes may thus serve as anode and cathode with a view to the activation of the organic light-emitting layer placed between this pair of electrodes. This OLED diode construction is advantageous in that it allows a plurality of emission colors to be produced, depending on the choice of the materials of the organic light-emitting layers. It is however disadvantageous as regards its production cost and the potential loss of light produced by each electrode pair through the other layers. This teaching also does not seem to address the question of the electrical connection of the electrodes with a view to supplying them with power.
Published patent document US 2014/0056020 A1 discloses a luminous module for an automotive vehicle, comprising a series of areal OLED light sources. These OLED diodes are placed circularly. With reference to FIG. 4 and paragraphs [0034] and [0035] of this document, a generally extensive luminous module may comprise a plurality of, in the present case two, OLED diodes able to be activated independently of one another. Each of these OLED diodes may moreover be divided into a plurality of portions or segments. However, this teaching does not describe in any further detail the division of an OLED diode into a plurality of segments.